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Several compounds of 3,9-dialkylxanthines were prepared from 1-methyl-6-chlorouracil via nucleophillic reactions with different aliphatic amines, followed by nitrosation, reduction, formaylation and finally dehydrocyclization. On the other hands, a series of 8-aryl-3,9-dimethylxanthines were synthesized by dehydrocyclization of 5-arylamido-1-methyl-6-methylaminouracils either by fussion or oxidation of 5-arylidineamino-1-methyl-6-methylaminouracils using sodium periodate. Phosphoryl chloride was found to be uneffective reagent for dehydrocyclization that, gave another products from 1,3-oxazolo [5,4-d] pyrimidines.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Pyridazine Derivatives and Related Compounds.Part 5. Pyrazolo(3,4-c) pyridazine: Synthesis and Some Reactions.-The pyrazolo(3,4-c)pyridazine (I) is acylated with (II) or alkylated with the phenacyl bromides (IV) to produce the carboxamides (III) or the amino ketones (V). The imines (VII) are prepared from (I) by reaction with the aromatic aldehydes (VI) in refluxing butanol. Cyclocondensation reaction of (I) with acetylacetone (VIII), ethyl cyanoacetate (X), ethyl acetoacetate (XII), diethyl malonate (XIV), the arylidenemalononitriles (XVI), and the ethyl arylidenecyanoacetates (XX) yields tricyclic pyrazoles as outlined in the reaction scheme. The tetracycle (XIX) is synthesized by cyclization of the amino nitrile (XVIIa) with formamide (XVIII). -(DEEB, A.; BAYOUMY, B.; ESSAWY, A. E.-N.; FIKRY, R.; Heterocycles 32 (1991) 5, 895-900; Dep. Chem., Fac. Sci., Univ., Zagazig, Egypt; EN)

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.